Conventional hoods or shrouds on small agricultural vehicles such as lawn and garden tractors or other grass or vegetation mowing machines typically enclose an engine, cooling system, and other vehicle components. Such vehicles commonly utilize liquid cooled internal combustion engines which generate heat during their operation. Liquid cooled engines employ pressurized coolant circulated through the engine to absorb heat. The heated coolant is subsequently passed through a heat exchanger such as a radiator to dissipate heat from the coolant to the atmosphere, after which the coolant is re-circulated to the engine for further cooling. As the coolant is passed through the heat exchanger, air flows through the heat exchanger to absorb heat and carry it out into the atmosphere. Air is commonly drawn or propelled through the radiator by use of a fan.
The capacity of a cooling system in such a vehicle depends on many factors including the velocity and volume of air flowing through the heat exchanger, as well as the distribution of the air flow over the available heat exchange surface of the radiator. Since these vehicles may be used in cutting grass or other vegetation, the air used to cool the radiator is frequently contaminated with dust, grass clippings and similar debris. Typically, such vehicles will include a grille or grilles having a screen to reduce debris present in the cooling air while allowing the air to pass into the area enclosed by the hood to cool the engine by interaction with the radiator.
In recent years, regulations are limiting allowable emissions from internal combustion engines of lawn and garden tractors, mowers and other agricultural and/or work vehicles. Due at least in part to these regulations, efforts have been made to increase the area of the cool air intake on the vehicle hood, and to increase the air flow through the heat exchanger. However, increasing the area of the air intake may result in more grass clippings, debris and other materials being sucked toward and/or into the air intake during machine operation. The materials may pile up in the air intake, restricting air flow, and may even ignite. There is a need for a larger cool air intake for a lawn and garden tractor, mower, and other small vehicle that will allow greater air flow without sucking up and/or ingesting grass clippings, debris and other materials that may restrict flow.
Additionally, there is a need to reduce or limit the noise emitted into the environment from engines of small lawn and garden tractors, mowing equipment and other small agricultural vehicles. Efforts to reduce noise levels include the design of quieter engines, and improvements to the hoods or shrouds intended to help contain or muffle engine noise. Larger air intakes, however, may limit these other noise reduction efforts. There is a need for a larger cool air intake for a lawn and garden tractor, mower, and other small agricultural vehicle that will help limit engine noise emitted into the environment.